As kids, granny always used watered-down jam in its pot with a single small hole in the tin lid for them to climb in.
I'm not sure about the lemon in your mix because I thought they were after the sweet, not the sour, if you know what I mean. Is there anything obvious I'm missing?
You're going to be doing well in any case though, if you can tempt a wasp away from an almost-pure sugar confectionery, with anything short of rotten meat.
That said, I'll bet there is a scent somewhere they simply can'r resist, that isn't just sugar...
Maybe the light from one of those bug-catching, high-energy, zapping machines some shops use...